My primary home machine loses network connectivity for a very brief moment once or twice a day. Here's what I've observed over the past few months:
- Seems to happen every 12 hours after a restart
- Disconnect is very, very brief. Putty sessions, online games, or other applications that require a consistent connection disconnect but it's rare that I can see a ping fail when everything else disconnects.
- Does not coincide with network problems on other machines (Xbox/media PC/wife's PC).
Other details about my system and home network:
- Windows 7
- Asus motherboard (couple generations old) with onboard ethernet
- Ethernet > wired hub > wireless router > cable modem (wife's PC is connected to the same hub and does not have the problem, at least not on the same schedule)
Things I've tried (and will probably now try again just in case)
- Restore network card driver (I'm in the process of finding a specific one for my motherboard)
- Tinkered with power saving settings in the ethernet card drivers.
- Fully up-to-date Windows install.
- Static IP address reserved by the wireless router running DHCP
- I'm not 100% sure, but I think this problem persisted across Windows OS upgrades (from Vista to Windows 7 a few months back)
By far the weirdest part is that it seems to happen every 12 hours. Like clockwork, I can predict that I'm going to disconnect from any persistent online connection if I know the last time I restarted my machine.
I caused my own problem long ago when trying to set static IP addresses in my home. I have a Netgear Router (WGR614v9) and I played with the Address Reservation feature. In addition, I manually set the IP address I wanted to have on my machine using the normal network card properties. Setting the IP address manually is what seems to have caused the conflict.
Finally looked in the Windows Event Viewer and the culprit was quickly identified. At time of restart and every 12 hours later, the following error appeared:
The IP address lease 192.168.1.20 for the Network Card with network address XXXXXXXXXX has been denied by the DHCP server 192.168.1.1 (The DHCP Server sent a DHCPNACK message).
I accidentally fixed it for all affected machines by changing the start address of the DHCP server on the router (increased it from 20 to 30). That seemed to kick all the manual entries out and set them back to automatic obtain mode.